Modern cardboard glazing brushes are manufactured in such a way that a steel cylinder, revolving on bearings at its ends, and with a length of 1500-10,000 mm, acts as a frame section for the brush roller. This cylindrical brush roller weighs 400-4000 kg, depending on its construction. The frame section of the brush roller is covered with plates made from about 10 mm thick aluminum, the width of which is about 100 mm, and the length 1000 mm. The plates, which are bent to the form of the outer surface of the cylinder, are secured with screws in rows to the surface of the roller brush. Holes with a diameter of about 5 mm are drilled in the aluminum at about 10 mm centers, and horsehairs from a horse's mane, with a length of about 60 mm from the surface of the aluminum plate, are attached to the hole by the traditional hand-binding method. The aluminum plates made in this way are first brushed with thin glue on the underside, which partly penetrates the fibers in the drilled holes, binding the individual fibers to one another. In addition, the underside of the plates is brushed with a thick layer of polyurethane, which prevents the brush from unravelling if the binding wire breaks. This method, which is in use at present, is, however, a quite expensive and slow method of manufacture, due to the large amount of handwork. A brush roller that must be sent for re-brushing must first of all be removed from the cardboard machine and sent to a brush factory. There the aluminum plates are removed from the roller brush and the polyurethane on the underside of the aluminum plates is either dissolved or ground away, after which the remaining fibers are twisted out of the holes and the holes in the aluminum plate are individually drilled olean before re-binding. There are 40,000-120,000 holes in a single roller brush, depending on its size. After binding and re-gluing, the plates are once again attached to the surface of the roller brush and the uneven ends of the fibers remaining from hand binding are levelled to their correct length and the roller brush is balanced before being returned to the cardboard mill. Due to this time-consuming re-brushing cardboard mills have had to keep extra brush rollers, because some of the rollers must always be re-brushed. The long delivery dates have also been a great problem.